The present invention relates to manufacturing equipment and manufacturing processes utilizing a continuous web of material. For example, the present invention may be used to reinforce portions of flexible packaging material. More specifically, the present invention relates to a system and process for reinforcing portions of a web, which can be supplied to subsequent processing equipment and operations.
Many web-based processes presently exist for various types of manufacturing. In each of these processes, bulk raw materials are supplied to various systems in a web format for further manipulation or processing. These bulk supplies of material often take the form of very large rolls which can then be unwound appropriately to create a web. More specifically, the material is unwound and fed into the processing machines, forming a web. In the packaging industry, these webs often take the form of plastics which will be formed into bags, containers or other enclosures. For example, the supply web may be wrapped around existing products, and then sealed at three or four edges to completely enclose the particular product.
Web manufacturing processes are typically very desirable due to the high speeds and efficiencies which can be achieved. For example, it is fairly easy to move material webs along a desired path using various rollers, including handling rollers and drive rollers. Similarly, in-line cutters and sealers can very easily be incorporated into these manufacturing processes as well. Because these operations are being done xe2x80x9cin linexe2x80x9d, they can be very quickly accomplished. It is fairly well known, however, that operations transverse to the web are less easily carried out and more complicated.
In these web-based processes, the actual material being used will dictate the capabilities and constraints of possible activities. Ideally, the material web is flexible and relatively strong. Consequently, material can be pulled through various rollers and various manufacturing apparatus without the fear of breaking or severing. Conversely, if a material is too rigid, it does not easily move through the manufacturing process, and is not easily manipulated. Further complications are encountered when this relatively heavy or rigid material must be cut or severed in any way. More specifically, it is difficult to achieve precise cuts of this more rigid material, especially when attempting to cut in a direction transverse to the web. Further, when working with a web that is quite wide, these transverse cuts become fairly long, which creates significant difficulties. Existing cutting mechanisms are not capable of precisely creating these long cross-web cuts.
Another complication of web-based manufacturing processes is the necessity to reinforce certain portions of the web. In particular, it may be desirable to reinforce only certain portions of the web, due to later operations that may be performed on only a portion of the web. For example, it may be desirable to reinforce the seal region where various layers of material are joined together. Reinforcing only a portion of the web introduces positioning and alignment complications however. As can be easily appreciated, this reinforcement operation becomes particularly difficult when it must be positioned transverse to the web. Additionally, the small strips of reinforcing material typically used are often difficult to handle.
One approach to reinforcing web at predetermined locations is to utilize a preformed roll of reinforcing material and applying it at appropriate locations. This roll of reinforcing material is specifically configured for this purpose and is typically much smaller than the actual web itself For example, one typical application may require a web approximately 2 to 4 feet wide, but may require reinforcing strips only I inch wide. When purchased as exclusive rolls of reinforcing material, these rolls are specifically produced in the desired narrow width. While this affords some manufacturing efficiencies by utilizing pre-sized reinforcing material, additional cost is inherently added to the process. These prefabricated xe2x80x9cnarrowxe2x80x9d rolls of reinforcing material are necessarily more expensive than similar product purchased in larger bulk format. Consequently, it would be desirable to utilize a more cost effective method of manufacturing which utilizes larger bulk materials. This is particularly true when the reinforcing material itself is a heavier, more expensive product to begin with.
In addition to the additional cost, when incorporating cross web reinforcement using these narrow rolls, the process is inherently slow. Material must be moved in a direction transverse to the web, rather than in line with the web. As with all web manufacturing, it is highly desirable to have all operations moving along with the web.
While the desirability of using bulk reinforcing materials may appear obvious, this does introduce more significant cutting and manipulating operations, as outlined above. Present day equipment is not capable of efficiently producing the necessary reinforcing strips from bulk webs of material.
In order to provide an efficient and cost effective method for reinforcing selected portions of a web, the present invention provides a mechanism which utilizes a large format supply of reinforcing material to selectively reinforce portions of a primary web. In order to accomplish this reinforcement the present invention includes a primary web handling system and a secondary web handling system, a cross web shear, a strip handling system and a laminating device. The primary web handling system handles the main web of packaging material, or primary web, which will be reinforced for later operations.
In order to provide this reinforcement, reinforcing strips are produced from the secondary web and then laminated to the primary web. Specifically, the secondary supply web provides reinforcing material to the cross web shear which cuts the secondary web into reinforcing strips of predefined width. Subsequently, this strip of reinforcing material is provided to a handling mechanism for moving the reinforcing strip to a predetermined location for attachment to the primary web. The laminating device is then utilized to attach this reinforcing strip.
To accomplish the complicated task of cross web cutting, the cross web shear of the present invention is uniquely configured. The cross web shear includes a radiused blade and a cam follower structure in order to initiate a single point cutting action. The cam follower structure, and all related driving devices, move the blade through a predetermined rocking type motion. By using the radiused cutting edge of the blade in this rocking type motion, only a single point of the blade is actually cutting at any particular point in time. This configuration allows for precise cross web cutting of the reinforcing material itself into the desired reinforcing strips.
In order to appropriately reinforce the primary web, the handling mechanism includes a vacuum manifold structure to grab the reinforcing strip and move it to its desired location. In one particular application, this reinforcing strip is relatively narrow and small compared to the primary web. Consequently, moving and handling of this component is complicated. This is especially true when desired precision is necessary. The vacuum manifold is capable of precisely capturing the reinforcing strip and moving it via an attached positioning device. The positioning device is then capable of moving the manifold to a desired location which is adjacent the laminating device. Lamination of the reinforcing strip can then easily be accomplished.
It is an object of the present invention to create a device for reinforcing a primary web at predetermined locations.
It is a further object of the present invention to provide a cross web shear capable of cutting reinforcing material into reinforcing strips of a desired size. The cross web shear fabricates these reinforcing strips from a bulk supply web and incorporates precision cuts to control the size and configuration of the reinforcing strip itself.
It is a further object of the present invention to create reinforcing strips from a bulk stock of reinforcing material. This reinforcing material supply can be provided in a secondary web format for efficient and cost effective creation of reinforcing strips.
It is a further object of the present invention to create reinforcing strips using a cross web shear, appropriately position these reinforcing strips adjacent to a primary web, and attach these reinforcing strips to the primary web. Consequently, the primary web is reinforced at predetermined locations to easily accommodate further operations.